Residency · Residency · Psychiatry

Generalized Anxiety Disorder and Panic Disorder

Generalized Anxiety Disorder (GAD)

DSM-5-TR Criteria

Excessive anxiety and worry about multiple events or activities, occurring more days than not for at least 6 months. Difficulty controlling the worry. Three or more of the following (only one in children): Restlessness or feeling keyed up. Easily fatigued. Difficulty concentrating or mind going blank. Irritability. Muscle tension. Sleep disturbance. Causes clinically significant distress or functional impairment. Not attributable to substance use, medical condition, or another mental disorder.

Cognitive-Behavioral Model of GAD

Borkovec's avoidance model: worry functions as cognitive avoidance of more distressing emotional processing; worry is predominantly verbal-linguistic (not imagistic), suppressing autonomic arousal. Dugas' intolerance of uncertainty model: core feature is intolerance of uncertainty; patients with GAD respond to ambiguity with catastrophic worry. Wells' metacognitive model: distinguishes Type 1 worry (about external events) from Type 2 worry (worry about worry -- "meta-worry"); positive beliefs about worry perpetuate the cycle. All models inform different CBT intervention targets.

Pharmacotherapy for GAD

First-line:. SSRIs: escitalopram, sertraline, paroxetine (all have evidence; escitalopram best tolerated) SNRIs: venlafaxine XR, duloxetine (both FDA-approved for GAD) Second-line:. Buspirone: 5-HT1A partial agonist; anxiolytic without sedation, dependence, or cognitive impairment; onset 2-4 weeks; most effective in benzodiazepine-naive patients. Pregabalin: alpha-2-delta calcium channel ligand; evidence from European trials; not FDA-approved for GAD in the US; caution with abuse potential. Hydroxyzine: antihistamine; short-term anxiolytic; sedating. Adjunctive/augmentation:. Benzodiazepines: effective but reserved for short-term use or refractory cases due to dependence risk. Mirtazapine: useful when insomnia and appetite loss are prominent. Quetiapine: evidence for GAD but metabolic risks limit use. Not recommended: beta-blockers (no evidence for generalized anxiety; may help performance anxiety)

Psychotherapy for GAD

CBT: most robust evidence; includes psychoeducation, cognitive restructuring (challenging catastrophic predictions), relaxation training, worry exposure, behavioral experiments. Applied relaxation: progressive muscle relaxation applied to anxiety-provoking situations. Acceptance and Commitment Therapy (ACT): emerging evidence; focuses on acceptance of anxious thoughts rather than control. Combination pharmacotherapy + CBT may be superior to either alone for moderate-severe GAD.

Panic Disorder

DSM-5-TR Criteria

Recurrent unexpected panic attacks: abrupt surges of intense fear or discomfort peaking within minutes, with four or more of the following: Palpitations or accelerated heart rate. Sweating. Trembling or shaking. Shortness of breath or smothering. Feelings of choking. Chest pain or discomfort. Nausea or abdominal distress. Dizziness, unsteadiness, lightheadedness, or faintness. Chills or heat sensations. Paresthesias. Derealization or depersonalization. Fear of losing control or "going crazy". Fear of dying. At least one attack followed by >=1 month of persistent concern about additional attacks, worry about consequences, or significant behavioral change (avoidance) Not attributable to substance use, medical condition, or another mental disorder.

The Cognitive Model of Panic (Clark, 1986)

Panic arises from catastrophic misinterpretation of normal bodily sensations. Cycle: bodily sensation (e.g., palpitation) --> catastrophic interpretation ("I'm having a heart attack") --> anxiety --> more bodily sensations --> escalating catastrophic interpretation --> panic attack. Hypervigilance to somatic cues (interoceptive sensitivity) perpetuates the cycle. Avoidance of situations associated with panic reinforces fear and maintains the disorder.

Agoraphobia

Frequently comorbid with panic disorder but is a separate diagnosis in DSM-5-TR. Fear or avoidance of situations where escape might be difficult or help unavailable: public transportation, open spaces, enclosed spaces, crowds, being outside the home alone. Can occur without panic disorder (and vice versa)

Pharmacotherapy for Panic Disorder

First-line: SSRIs (sertraline, paroxetine, fluoxetine, escitalopram) or SNRIs (venlafaxine XR) Start at LOWER doses than for depression (e.g., sertraline 25 mg) to avoid initial activation/worsening of panic. Full therapeutic response takes 4-8 weeks. Benzodiazepines: rapid efficacy for acute panic; alprazolam and clonazepam have most evidence but dependence risk is high; use as bridge therapy while SSRI takes effect. TCAs: imipramine and clomipramine effective but side effect burden limits use. Not effective: buspirone (no evidence for panic disorder), beta-blockers (no evidence for spontaneous panic)

Psychotherapy for Panic Disorder

CBT for panic disorder: the gold standard psychotherapy. Psychoeducation about the fight-or-flight response and the safety of panic sensations. Cognitive restructuring of catastrophic interpretations. Interoceptive exposure: deliberately inducing feared bodily sensations (hyperventilation, spinning, breathing through a straw, physical exercise) to extinguish conditioned fear responses. In vivo exposure: graduated exposure to avoided situations (agoraphobic avoidance) Panic-focused CBT has response rates of 70-90% and superior long-term outcomes compared to pharmacotherapy alone.

Interoceptive Exposure Techniques

Hyperventilation (30 seconds): induces lightheadedness, tingling, derealization. Breathing through a straw (2 minutes): induces air hunger. Spinning in a chair (1 minute): induces dizziness. Running in place or stair climbing: induces tachycardia, shortness of breath. Staring at a light then reading (1 minute): induces visual disturbances. Patients practice until the conditioned fear response to these sensations extinguishes.

<image> A circular diagram illustrating the cognitive model of panic (Clark's model). Show the cycle: trigger stimulus (bodily sensation or external cue) --> catastrophic misinterpretation --> anxiety/fear --> physiological arousal (increased heart rate, hyperventilation, sweating) --> more bodily sensations --> back to catastrophic misinterpretation. Include intervention points where CBT techniques break the cycle: cognitive restructuring targets the misinterpretation step, interoceptive exposure targets the conditioned fear response, and psychoeducation targets the trigger appraisal. Clean clinical education style with arrows and color coding. </image>

<image> A treatment algorithm comparing GAD and panic disorder management. Two parallel flowcharts side by side. For GAD: first-line (SSRI/SNRI + CBT), second-line (buspirone, pregabalin), adjunctive (benzodiazepine short-term, mirtazapine). For panic disorder: first-line (low-dose SSRI/SNRI + panic-focused CBT with interoceptive exposure), bridge therapy (benzodiazepine short-term), second-line (TCA). Show shared and distinct elements. Include response assessment timepoints. Color-coded by treatment modality. </image>

<image> An infographic showing interoceptive exposure exercises for panic disorder. List each exercise (hyperventilation, breathing through a straw, spinning, running in place, staring at a light) with an illustration of the exercise, the bodily sensations it produces, and the catastrophic cognitions it targets. Include a hierarchy format showing how exercises are typically ordered from least to most anxiety-provoking. Include a pre/post anxiety rating scale (SUDS). Clinical psychotherapy education style. </image>

Clinical Pearls

GAD and panic disorder are the most common anxiety disorders in clinical practice and are frequently comorbid with each other and with MDD. Start SSRIs at lower-than-usual doses for panic disorder (e.g., sertraline 25 mg, escitalopram 5 mg) -- standard starting doses can trigger a paradoxical increase in panic symptoms. Buspirone is effective for GAD but NOT for panic disorder -- this is a common prescribing error. Interoceptive exposure is the most powerful component of CBT for panic disorder -- it directly targets the conditioned fear response to bodily sensations. Benzodiazepines provide rapid relief but should be used as bridge therapy only; long-term use undermines exposure-based treatment by providing a "safety behavior". The medical workup for new-onset panic should include TSH, ECG, and consideration of pheochromocytoma, arrhythmia, hyperthyroidism, and substance use. GAD patients often present with somatic complaints (muscle tension, headaches, GI distress, fatigue) rather than explicitly reporting worry -- screen for worry in somatic symptom presentations.

References

• Craske MG, et al. Treatment for GAD. In: Treatments That Work. Oxford University Press; 2006.
• Clark DM. A cognitive approach to panic. Behav Res Ther. 1986;24(4):461-470.
• Bandelow B, et al. World Federation of Societies of Biological Psychiatry (WFSBP) guidelines for treatment of anxiety disorders. World J Biol Psychiatry. 2008;9(4):248-312.
• Hofmann SG, Smits JA. Cognitive-behavioral therapy for adult anxiety disorders: a meta-analysis of randomized placebo-controlled trials. J Clin Psychiatry. 2008;69(4):621-632.
• Borkovec TD, et al. The nature of worry in generalized anxiety disorder. Behav Res Ther. 1983;21(1):9-16.

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